Mobile terminal device and network connection control method

ABSTRACT

A mobile terminal device includes a wireless communication interface and a wired communication interface. The device further includes a wired communication determination unit configured to determine whether or not communication with a network by the wired communication interface, an external power source supply unit configured so as to be supplied power from the outside for charge or replacement of a built-in battery, a power supply state detection unit configured to detect that a state, in which power is supplied from the outside to the external power source supply unit, is attained, and a control unit configured to set a state in which the wireless communication interface is available regardless a determination result of the wired communication determination unit after the power supply state detection unit detects the state in which the power is supplied from the outside.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromprior Japanese Patent Application No. 2007-170835, filed Jun. 28, 2007,the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile terminal device configured tobe connected to a network, and relates to a control method forconnecting such a terminal device to the network.

2. Description of the Related Art

In recent years, a mobile terminal device such as an electronic stillcamera (hereinafter referred to as a digital camera) with a wirelesscommunication interface to be wirelessly connected to a network such asLAN, etc., mounted thereon has become widely used.

A first object of mounting a wireless communication interface is toachieve data transfer without a wire.

Further, in recent years, a public wireless LAN service (called a hotspot, etc.) has been in the process of being prepared. Thus,transferring data of an acquired image to a server, etc., on theInternet from a place of visit via the foregoing LAN service by mountingthe wireless communication interface on a portable terminal deviceitself such as a digital camera has been realized. This is a secondobject of mounting the wireless communication interface.

A third object is to connect the digital camera to a home (householdelectrical appliance) network through the wireless communicationinterface mounted on the mobile terminal device such as a digitalcamera. Thereby, the mobile terminal device becomes able to access imagedata stored in the digital camera without having to operate the digitalcamera from a personal computer (PC) or a television receiver, etc.,connected to the network and becomes convenient.

However, an existing digital camera with the wireless communicationinterface mounted thereon has to issue a start instruction by means of aswitch on the side of the digital camera in order to start an operationof the wireless communication interface and this causes a userinconvenience.

To solve the problem of the start by means of the switch, an always-onwireless communication interface is a possible approach. However, sincewireless communication consumes a large volume of power even inreception, the always-on wireless communication interface poses aproblem that a battery dies at short times. Even where constantconnection to the network is enabled and PCs and television receiversconnected to the networks are allowed to access the images stored in thedigital camera, the above-mentioned short life of the battery becomes aproblem.

Therefore, US 2006/0025105A1 has proposed a terminal device and awaiting operation control method which automatically starts a wirelesswaiting operation in addition to a start of supply of power form anexternal power source in order to solve the problem of power consumptionand a troublesome operation of a start of waiting for wirelesscommunication.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda mobile terminal device configured to connect to a network, comprising:

a wireless communication interface configured to connect to the networkthrough wireless communication;

a wired communication interface configured to connect to the network oneof directly and indirectly through wired connection;

a wired communication determination unit configured to determine whetheror not communication with the network by the wired communicationinterface;

an external power source supply unit configured to be supplied powerfrom the outside for one of charge and replacement of a built-inbattery;

a power supply state detection unit configured to detect that a state,in which power is supplied from the outside to the external power sourcesupply unit, is attained; and

a control unit configured to set a state in which the wirelesscommunication interface is available regardless a determination resultof the wired communication determination unit after the power supplystate detection unit detects the state in which the power is suppliedfrom the outside.

According to a second aspect of the present invention, there is provideda network connection control method in a mobile terminal device whichincludes a wireless communication interface configured to connect to thenetwork through wireless communication, a wired communication interfaceconfigured to connect to the network one of directly and indirectlythrough wired connection, and an external power source supply unitconfigured to be supplied power from the outside for one of charge andreplacement of a built-in battery, comprising:

detecting whether a state, in which power is supplied from the outsideto the external power source supply unit, is attained; and

making the wireless communication interface is available regardless ofpossibility of communicating with the network by the wired communicationinterface after detecting the state in which the power is supplied fromthe outside.

According to a third aspect of the present invention, there is provideda mobile terminal device configured to connect to a network, comprising:

wireless communication interface means for connecting to the networkthrough wireless communication;

wired communication interface means for connecting to the network one ofdirectly and indirectly through wired connection;

wired communication determination means for determining whether or notcommunication with the network by the wired communication interfacemeans;

external power source supply means for being supplied power from theoutside for one of charge and replacement of a built-in battery;

power supply state detection means for detecting that a state, in whichpower is supplied from the outside to the external power source supplymeans, is attained; and

control means for setting a state in which the wireless communicationinterface means is available regardless a determination result of thewired communication determination means after the power supply statedetection means detects the state in which the power is supplied fromthe outside.

According to a fourth aspect of the present invention, there is provideda network connection control method in a mobile terminal device whichincludes wireless communication interface means for connecting to thenetwork through wireless communication, wired communication interfacemeans for connecting to the network one of directly and indirectlythrough wired connection, and external power source supply means forbeing supplied power from the outside for one of charge and replacementof a built-in battery, comprising:

a step of detecting whether a state, in which power is supplied from theoutside to the external power source supply means, is attained; and

a step of making the wireless communication interface means is availableregardless of possibility of communicating with the network by the wiredcommunication interface means after detecting the state in which thepower is supplied from the outside.

Advantages of the invention will be set forth in the description whichfollows, and in part will be obvious from the description, or may belearned by practice of the invention. Advantages of the invention may berealized and obtained by means of the instrumentalities and combinationsparticularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1A is an outer appearance view viewed from the front face that is asubject side of a digital camera as a first embodiment of a mobileterminal device regarding the invention;

FIG. 1B is an outer appearance view viewed from a rear face that is anoperation side of a user of the digital camera;

FIG. 2 is a block diagram depicting an electrical configuration of thedigital camera;

FIG. 3 is a flowchart of a wireless communication routine to beperformed at prescribed timing in the digital camera;

FIG. 4 is a flowchart of a network connection start subroutine of FIG.3;

FIG. 5 is a flowchart of a network response subroutine of FIG. 3;

FIG. 6 is a flowchart of a file list creation subroutine in a digitalcamera as a second embodiment of the mobile terminal device regardingthe invention;

FIG. 7A is a view depicting a file storage configuration of an imagedata storage unit of the second embodiment;

FIG. 7B is a view depicting an example of a file list for opening topublic on a network of the second embodiment; and

FIG. 8 is a flowchart of a file list update subroutine of the secondembodiment.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an optimum form in order to embody the present inventionwill be described with reference to the drawings.

First Embodiment

As shown in FIGS. 1A and 1B, on the right hand side of a user, a releasebutton 12 for instructing image acquisition is provided on a top face ofa digital camera 10 as the first embodiment of a mobile terminal deviceregarding the invention. A power switch 14 for turning on/off a powersource of the digital camera 10 is provided at the next to the releasebutton 12.

A flash lump 16 and a lens 18 for taking in image acquiring light inimage acquisition are disposed on the front face of the digital camera10.

A wired connection connector 20 for connecting a wire for wiredcommunication and an external power source connector 22 for connecting awire for external power source supply are disposed on a side face of thedigital camera 10. However, in a case of a configuration in which poweris supplied by a non-contact power transmission using electromagneticinduction, the external power source connector 22 is not disposed.Positions of the connectors 20, 22 are not limited to the side face;they may be disposed on other side faces, the positions may be on therear face or the lower face of the digital camera 10. Further, theconnectors 20, 22 may be uncovered or have lids.

A color liquid crystal display device 24 for displaying a subject imageto be acquired, images and menu items, messages, etc., recorded in thedigital camera 10 in a reproduction mode are disposed on the rear faceof the digital camera 10. The rear face of the digital camera 10 isprovided with a cross-shape cursor button 26 for instructing selectionof the menu items or a change in operation state when the display device24 displays menu items for setting various operation conditions of thedigital camera 10. Further, the rear side has a menu button 28 forcalling menu items for setting the various operation conditions of thedigital camera 10. Other than this, the rear side includes a decisionbutton for instructing items which have been selected from the menuitems, and other buttons for instructing the operation state of thedigital camera 10.

Although it is not shown, a mechanism for mounting a memory card tostore the image data acquired with the digital camera 10 and a batteryis provided for on the lower face of the digital camera 10.

As an electrical configuration of the digital camera 10, as shown inFIG. 2, the camera 10 includes a control unit 30, a ROM 32, RAM 34, animage acquisition unit 36, a wireless communication circuit unit 38, anantenna 40, an operation unit 42, a display unit 44, and an image datastorage unit 46. Each of those units is mutually connected as shown inFIG. 2. The digital camera 10 has a power source circuit unit 48 tosupply power to each of the units. Further, the digital camera 10includes a power supply state detection unit 50, an external powersource supply unit 52, a wired communication circuit unit 54, a wiredconnection detection unit 56 and the foregoing wired connectionconnector 20.

The control unit 30 is a control unit for applying sequence control tothe digital camera 10 and operates in accordance with a program storedon the ROM 32.

The ROM 32 is a nonvolatile memory such as a flash ROM, and program datafor controlling the digital camera 10, various items of settinginformation, and a file list for opening to public on the network(virtual directory) given later are stored on the ROM 32.

The RAM 34 functions as a temporal buffering for digital image data tobe output from the image acquisition unit 36, as a work area to be usedfor computing by the control unit 30, and as an area for temporarilystoring every kind of setting, etc.

The image acquisition unit 36 includes the lens 18 for focusing incidentlight, a photoelectric converter (CCD, CMOS sensor, etc.) for convertingfocused light into an electric signal, and an analog-digital converter(an AD converter) for converting an analog electric signal output fromthe photoelectric converter into a digital electric signal.

The wireless communication circuit unit 38 is a wireless interfacecomposed of a high-frequency circuit unit, an encoding/decoding circuitunit, a buffer memory in wireless communication, etc., which arenecessary for the wireless communication. An antenna 40 is connected tothe circuit unit 38.

The operation unit 42 includes buttons and switches, for example, therelease button 12, the cursor button 26, the menu button 28, etc., andoutputs states of the buttons and switches and changes in the states aselectric signals.

The display unit 44 is composed of the color liquid crystal displaydevice 24 and its control circuit.

The image data storage unit 46 is a storage device for storing acquireddigital image data therein. The storage unit 46 may be configured tohave a nonvolatile memory such as a built-in flash ROM, or may beconfigured to have a memory card, etc., detachable from a main unit ofthe digital camera 10, and either configuration can be used.

The power supply state detection unit 50 is, as mentioned later, aconnection detection unit to detect that the power supply from theexternal power source becomes able.

The external power source supply unit 52 may be configured to directlysupply power through the contact connection by means of the externalpower source connector 22, or may be configured to supply power throughthe non-contact power transmission using the electromagnetic induction,and either configuration can be used.

The wired communication circuit unit 54 is a wired communicationinterface which is connected with a wire through the connector 20 andcommunicates with an external device. The circuit unit 54 may directlyconnect to the network through an Ethernet (registered trademark) cable,or may indirectly connect to the network via a PC connected through aUSB cable.

The wired connection detection unit 56 detects the connection of thecable (Ethernet cable or USB cable) to the wire connection connector 20.The detection unit 56 may have a configuration in which a mechanicalswitch is turned on by the connection of the cable to the connector 20,or may have a configuration in which a connection of a cable is sensedby a sensor using light, a magnetic field or an electric field, andeither configuration may be used. Supply of power through the USB cableat the same time of communication is a possible approach. To cope withsuch a case, the detection unit 56 has a function to detect a voltage ofa signal input from the cable connected to the connector 20 and toreport a wired connection to the control unit 30. A method for detectingthe wired connection by trying to actually perform wired communicationat described timing and depending on the response is a possibleapproach.

The wire connection connector 20 holds the cable in wired connection andalso transmits the signal from the cable to the wired communicationcircuit unit 54. The connector 20 connects the power to be supplied fromthe cable to the power source circuit unit 48.

The power source circuit unit 48 includes a battery, DC-DC converter anda battery check circuit, detects that the power switch 14 has beenturned on, and supplies power to each of the aforementioned units. In acase in which the circuit unit 48 can be supplied power from theexternal power source supply unit 52, and in a case in which the circuitunit 48 can be supplied power in wired connection, the circuit unit 48also has a function to charge the battery. Supplying the power suppliedform the outside without intervention of the battery at the same time ofthe battery charge operation can be also used. Further, the circuit unit48 has a function of detecting the remaining capacity of the battery.

The digital camera 10 having such a configuration has a function oftransmitting the acquired digital image to other electronic devicethrough wired communication or wireless communication.

The three usable patterns for the detection method by the power supplystate detection unit 50 are described as follows.

1) A method for directly detecting a voltage to be applied to theexternal power source supply unit 52.

2) A method for detecting a magnetic filed or an electric field in acase in which the external power source supply unit 52 is configured tosupply power by a non-contact power transmission unit electromagneticinduction.

3) A method for detecting that the supply of power becomes able bysensing mechanical engagement into an external power source supplydevice (not Shown) thorough a sensor (not shown) using a magnetic fieldor an electric field. More specifically, for example, if the externalpower source supply device is a cradle, an optical sensor senses theengagement into the cradle by means of an optical sensor. Or afterembedding a magnet in the cradle, this method may sense the magnet bymeans of a magnetic sensor, or after embedding an RFID tag in thecradle, this method may sense the tag by reading the tag. The cradle maybe actualized by a small sized connector, if its shape has a space whichcan perform the aforementioned sensing.

The following will describe operations of the wireless communicationinterface of the digital camera 10 configured in the aforementionedmanner.

A main routine of the digital camera 10 can separately perform thewireless routine shown in FIG. 3 at prescribed timing.

That is, in this routine, at first, the power supply state detectionunit 50 detects whether or not the digital camera 10 is in a state inwhich the digital camera 10 may be supplied power from an external powersource (Step S10). Here, if the supply from the external power source isdetected, the digital camera 10 starts up the power sources of unitsrequired to make a wireless connection including the wirelesscommunication circuit unit 38 and to access the inner data (Step S12).In other words, the circuit unit 38 is configured so as not to start itspower source even if the power switch 14 is turned on, and in a case ofdetection of the supply of the power from the external power source, thepower source of the circuit unit 38 starts its power source absolutely.In general, power on caused by a usual operation of the power switch 14,the power source circuit unit 48 supplies power to each of thefunctional units. Like this, in a case where the wireless communicationis made by detecting the supply from the external power source, it isnot always necessary to supply power to all units inside the digitalcamera 10. That is, it is enough to supply power only to the units(e.g., the wireless communication circuit unit 38, the control unit 30,the image data storage unit 46, etc.) which are necessary for makingwireless communication and accessing the inner data.

Conversely, if it is determined that power is not supplied from theexternal power source in Step S10, the wired connection detection unit56 determines whether or not the wired connection is available (StepS14). If the wired connection is available, it is assumed that thedigital camera 10 utilizes the wired communication by means of the wiredcommunication circuit unit 54, and the control unit 30 terminates thisroutine without starting up the power source of the wirelesscommunication circuit unit 38. The control unit 30 then returns to themain routine to proceed to a procedure of wired communication which isnot shown.

If the wired connection is not available, the control unit 30 determineswhether the power switch 14 is on or not (Step S16). In a case that thepower switch 14 is not on, the control unit 30 ends this routine toreturn the main routine. Conversely, if the power switch 14 is on, thecontrol unit 30 further determines whether a wireless switch is turnedon or not (Step S18). The wireless switch means a switch which gives aninstruction to a device when an operator intends to arbitrarily make thewireless communication turn on. The wireless switch may be a switchcomposed of a GUI of the display unit 44 and the operation unit 42, ormay be a switch composed of a single button. In the case of the latter,there is a low probability that something inside a bag touches thedigital camera 10 which is put in the bag to turn on both the powerswitch 14 and the wireless switch. Therefore, there is littlepossibility that the power source of the wireless communication circuitunit 38 is started contrary to user's expectation and the digital camera10 is connected to the network.

In a case where the wireless switch is not on, the wirelesscommunication routine ends to return to the main routine. Conversely, ina case where the wireless switch is on, the control unit 30 furtherchecks the remaining capacity by the power source circuit unit 48 (StepS20). If the remaining capacity of the battery is low, the control unit30 terminates this routine to return to the main routine. If theremaining capacity of the battery is sufficiently high, namely if theremaining capacity is higher than a prescribed capacity, the wirelesscommunication routine proceeds to Step S12 and starts up the powersource of the wireless communication circuit unit 38. That is, when theuser performs a usual start operation of the wireless communication, thepower source of the wireless communication circuit unit 38 is started.

While the embodiment has described a case that the control unit 30determines whether the wired connection is available, and if it isavailable, the digital camera 10 utilizes the wired connection and doesnot utilize the wireless communication, a major point of the inventionis to make the wireless communication available regardless of theavailability of the wired connection if the external power source cansupply the power. Therefore, Step S14 may be omitted to turn on/off thewired connection without relation to the wireless connection, and anenvironment in which the wireless connection and the wired connectionexist together may be established. Or, the wired connection may alwaysbe on, and a configuration, in which if the power source is connected,the wired connection may be turned off, is a possible approach.

The aforementioned Steps S16-S20 has described as one example of aprocedure, all the Steps S16-S20 are not always necessary and some ofthem may be arbitrarily omitted. For instance, if the user expects toalways turn on the wireless communication when the power switch 14 hasbeen on, Step S18 may be omitted.

When the power is supplied to the wireless communication circuit unit 38in Step S12, next, the control unit 30 confirms whether the file listfor opening to public on the network has been created on the ROM 32(Step S22). If the file list has not been created, the file list iscreated (Step S24). The file list is a list of files which have beenstored in the image data storage unit 46.

If it is determined that the file list for opening to public on thenetwork has been created in Step S22, or if the file list has beencreated in Step S24, next, the control unit 30 calls a networkconnection start subroutine to start the network connection through thewireless communication circuit unit 38 (Step S26).

The network connection start subroutine starts after clearing a networkconnection timer (not shown) disposed in the control unit 30 as shown inFIG. 4 (Step S26A). After this, the connection to the network by meansof the wireless communication circuit unit 38 is started (Step S26B).Then, it is determined whether or not the communication with the networkthrough the circuit unit 38, namely it is confirmed whether or not thenetwork connection has been established (Step S26C). If the networkconnection has been established, the control unit 30 ends this networkconnection start subroutine to return to a host routine.

Conversely, if the network connection has not been established yet, itis determined whether or not the time to be clocked with the networkconnection timer has passed a preset fixed time period (Step S26D). Ifit is determined that the fixed time period has not passed, theflowchart retunes to Step S26C. Conversely, if it is determined that thefixed time period has passed, the subroutine ends to return to the hostroutine.

Thus, after retuning to the routine shown in FIG. 3, it is determinedthat whether the connection to the network has been completed normallyor not (Step S28). If the connection has not been completed normally,the control unit 30 turns off the power sources of the units which arenecessary for the wireless connection including the wirelesscommunication circuit unit 38 and for the access to the inner data (StepS30). The wireless communication routine then ends and returns to themain routine.

Conversely, if the connection to the network has been completednormally, access from a network side connected through wirelessconnection becomes able. Then, it is determined whether any access fromthe network has been made or not (Step S32). If any access from thenetwork has made, namely if any access from an external device such as atelevision receiver connected to the network has been made, a responseto network subroutine is called to give a reply in response to accesscontent (Step S34). Then the wireless communication routine returns toStep S32. The detail of the response to network subroutine will bedescribed later. Like this, the digital camera 10 replies responses forthe request from the external device connected to the network ifnecessary.

In Step S32, if it is determined that any access has not been made fromthe network, the power supply state detection unit 50 detects whether ornot the digital camera 10 is in a state to be supplied the power fromthe external power source (Step S36). If the supply from the externalpower source is detected, the wireless communication routine returns toStep S32. Namely, the digital camera 10 does not turn off the wirelesscommunication connection during reception of power supply from theexternal power source in order to reduce the consumption of battery inwireless communication and achieve constant access from the networkcaused by always turning on the wireless communication.

Conversely, if it is determined that the external power source does notsupply power, since it is a case in which the wireless communication hasbeen turned on by the user's operation through Steps S14-S20, at first,it is determined whether or not the power switch 14 has been turned on(Step S38). If the Power switch 14 has not been turned on, the wirelesscommunication routine proceeds to Step S30 to turn off the power sourcesrequired to the wireless communication including the wirelesscommunication circuit unit 38 and to the access to the inner data. Thecontrol unit 30 then ends the wireless communication routine to retuneto the main routine.

Meanwhile, in the case of the power switch SW14 being on, the controlunit 30 further determines whether the wireless switch has been turnedon or not (Step S40). If the wireless switch has not been turned on, thewire communication routine proceeds to Step S30 to turn off the powersources of the units needed for the wireless communication including thewireless communication circuit unit 38 and for the access to the innerdata. The control unit 30 terminates this routine to retune to the mainroutine.

Furthermore, in a case of turning on of the wireless switch, the powersource circuit unit 48 checks the remaining capacity of the battery(Step S42). If the remaining capacity of the battery is low, thewireless communication routine also proceeds to Step S30 and turns offthe power sources of the units which are necessary to the wirelesscommunication including the circuit unit 38 and the access to the innerdata. The control unit 30 ends this routine to return to the mainroutine. If the remaining capacity of the battery is sufficiently high,the control unit 30 returns to Step S32.

The aforementioned Steps S38-S42 have described as one example, all theSteps S38-S42 are not always necessary and some of them may bearbitrarily combined. For instance, if it is assumed that the battery isused at the last moment for the wire communication without checking theremaining capacity of the battery, Step S42 may be omitted. If it isdetermined that the wireless switch has been turned on in Step S40, theprocessing may be returned to Step S32.

In the response to network subroutine to be called in Step S34, firstly,it is determined whether or not the access from the network is areference request for the file list for the opening to the public on thenetwork, as shown in FIG. 5 (Step S34A). If it is determined so, thecontrol unit 30 updates the file list created on the ROM 32 so as tomatch with the content of the current image data storage unit 46 (StepS34B). The control unit 30 then replies the updated file list to thenetwork (Step 34C). The external device such as a television receiverconnected to the network comes to know the files stored in the digitalcamera 10 from the replied file list, and becomes able to make requestsfor reading, writing or deleting the files.

If the access from the network is not the reference request for the filelist for the opening to the public on the network, it is determinedwhether or not the access is a file read request for requesting readinga specified file (Step S34D). If the access is so, it is determinedwhether or not the specified file is in the file list which has beencreated on the ROM 32 (Step S34E). If the specified file is in the filelist, the control unit 30 reads an entity file of the file from theimage data storage unit 46 to make a reply (Step S34F). Conversely, ifsuch a required file is not in the file list, the wireless communicationroutine proceeds to the next step S34G. If the required file is not inthe file list, an error message such as a ‘File is not found.’ may bereplied although it is not especially shown. This case may occur in acase in which a corresponding-entity file has been deleted in accordancewith an operation on the side of the digital camera 10 or a deletionrequest from other device on the network after sending the file list inStep S34C. In such a case, the external device on the network may obtainthe update file list for the opening to public on the network bytransmitting a reference request for the file list again to the digitalcamera 10.

If the access from the network is not the file read request, it isdetermined whether the access is a file write request or not (StepS34G). If the access is the file write request, the control unit 30stores an entity of the file in the data storage unit 46 (Step S34H).The control unit 30 then updates the file list in relation to therelevant file (Step S34I).

If the access from the network is not the file write request, it isdetermined whether or not the access is a file deletion request forrequiring deletion of a specified file (Step S34J). If the access is thefile deletion request, it is determined whether or not thecorresponding-entity file is in the image data storage unit 46 (StepS34K). If the corresponding-entity file is not in the storage unit 46,namely if the entity file has already been deleted, the control unit 30updates the file list so as to match with a present situation (StepS34L). If the corresponding-entity file is in the storage unit 46, thecontrol unit 30 deletes the entity file (Step S34M). After this, thecontrol unit 30 proceeds to Step S34L to update the file list.

Needless to say, the file list for the opening to the public on thenetwork is updated at every time when the digital camera 10 acquires animage to create a file of image data, and also at every time when anoperation from the operation unit 42 deletes a file of unnecessary imagedata.

Deleting the file in response to an off operation of the power switch 14and newly creating the file list when the power switch 14 is turned onis a possible approach. If the image data storage unit 46 is configuredto have a memory card, etc., which is detachable from the main unit ofthe digital camera 10, as the image data storage unit 46, replacement ofthe memory card makes contents of the file list and of the storage unit46 completely different from each other. In this case, re-creating thefile list by turning on/off the power switch 14 enables avoiding theoccurrence of such a difference.

Of course, creating and storing the file list for each memory card whileassociating with IDs, etc., of the memory cards may be acceptable. Withthe creating and storing performed, there is no need to re-create thefile list for every time when the power switch 14 is turned on/off.

As mentioned above, according to the first embodiment, if the power issupplied from the external power source, regardless of the presence orabsence of a connection through a wired line, and regardless of theremaining capacity of the battery, etc., it is assumed that the digitalcamera 10 is present indoor or a range in which the home (householdelectrical appliance) network is available, the digital camera 10automatically starts the wireless communication circuit unit 38.Thereby, a reception waiting state is maintained so that the file of theacquired image data stored in the image data storage unit 46 can beaccessed. Thus the user's convenience is enhanced. That is, even when arelay device of a wired LAN or a PC on a halfway of a wired line is notoperated, the digital camera 10 is connected to the home network, etc.,through the wireless connection, becomes able to access the inner datafrom an external device such as a PC and a television receiver, namelyfrom the side of the network.

If the power is not supplied from the external power source, it isassumed that the digital camera 10 is not in the range in which the homenetwork is available, and the operation of the wireless communicationcircuit unit 38 is stopped. Thereby, since the amount of the consumedpower may be reduced, such a case may prevent the life time of thedigital camera 10 from becoming short.

Second Embodiment

Next, the second embodiment of the invention will be described.

In recent years, a flash ROM such as a detachable SD memory card may beused as an image data storage unit 46 of a digital camera 10. Thecapacity of the flash ROM has become large at a low cost in recentyears. The flash ROM can be used not only in a digital camera but alsoin various devices such as a music reproduction device, and a PC.Therefore, in using the flash ROM as the storage device 46 for a mobileterminal device such as a digital camera 10, there is a possibility thatnot only files of image data acquired by the user but also a variouskinds of files such as music, character information, video and a motionimage are each mixed.

Then, in the second embodiment, the mobile terminal device restrictsaccess from a network side to files stored in an image data storage unit46 by devising the file list for opening to public on a network to beupdated in foregoing Steps S34B, 34I, 34L so as to improve user'sconvenience.

Therefore, the configuration and operations of the mobile terminaldevice regarding the second embodiment are basically the same as thoseof the configuration and operations of the mobile terminal deviceregarding the first embodiment. The following will described only thecomponents differing from those of the first embodiment.

It is assumed that in operation for image acquisition, after the imagedata acquired by a image acquisition unit 36 is converted into aprescribed format such as JPEG which is compliant with, for example, aDCF standard that is a normal file system standard for a digital camera,image acquisition device information is added to the image data and theimage data is stored in the storage unit 46. In the embodiment, it isassumed that opening files to be released to the public on the networkare only image files which have been acquired with the digital camera10. Methods for identifying image files acquired with the digital camera10 are described as follows.

1) It is identified by means of metadata such as an exchangeable imagefile format (Exif). For instance, since the Exif data which is compliantwith an Exif standard that is a normal file format standard for adigital camera includes image acquisition device information, the methodutilizes this information. Not only the Exif data but also metadatadiffering from the Exif data may be embedded at a part of an image datafile.

2) In storing the acquired image data in the storage unit 46, the imagedata is stored in a specified folder to make it possible to access onlythe data stored in the specified folder from the network. Further, imagedata which has been acquired with the same type of image acquisitiondevices as that of the digital camera may be omitted by naming thespecified folders for each camera. A method for embedding individualcamera information into this folder name is an example, and any method,for example, a method for setting another associated storage area can beused as long as the folder is associated with the individual camerainformation.

In the digital camera 10 of the second embodiment of the mobile terminaldevice regarding the invention, in a file list creation subroutine to becalled in the foregoing Step S24, as shown in FIG. 6, at first, thedigital camera 10 creates an empty file list for opening to the publicon a network on the ROM 32 (Step S24A).

Then, the digital camera 10 retrieves an entity file in the storagedevice 46. (Step S24B). Here, it is determined whether or not theretrieved entity file is a file in a shared folder, namely in an openfolder (Step S24C). If the entity file is the file in the shared (open)folder, the file is registered in the created file list (Step S24D).

As mentioned above, the memory card as the storage unit 46 may be sharedwith a terminal such as a music player. As shown in FIG. 7A, image data,other than image data (e.g., of a file name ‘A***.jpg’ [*** isoptional]) acquired with the digital camera 10, such as music data(e.g., of a file name ‘***.Mp3’) may be stored in the memory card.Therefore, it is determined whether or not the entity file is a file ina prescribed specific shared (open) folder (e.g., a ‘Photo’ folder), andif it is so, the entity file is registered in the file list as shown inFIG. 7B.

In the foregoing Step S24C, if it has been determined that the entityfile is not a file in the shared (open) folder, further, it isdetermined whether the image acquisition device information of theretrieved entity file coincides with the device information of thedigital camera 10 (Step S24E). If both the information coincides witheach other, the subroutine proceeds to Step 24D given above to registerthe entity file in the file list for the opening.

In other words, even if the entity file is not a file in thepredetermined specific shared (open) folder [‘Photo’ folder], the entityfile may be a file of the image data, which has acquired with thedigital camera 10, like a file of a name ‘A010.jpg’ stored in a ‘Root’folder of FIG. 7A. If the entity data is an image data like this, theentity file is registered in the file list as shown in FIG. 7B. Sincethe file, which is created by other device does not coincide with thedevice information of the digital camera 10 as shown in FIG. 7A as afile name ‘M010.jpg’, the files created by other devices is not registerin the file for opening as shown in FIG. 7B.

It is determined whether or not all the entity files stored in thestorage unit 46 have been retrieved (Step S24F). If all the entity fileshave not been retrieved yet, the subroutine returns to Step 24B.Thereby, all the entity files stored in the storage unit 46 are appliedthe operations in Steps S24B-S24E.

After retrieving all the entity files stored in the storage unit 46, thecontrol unit 30 ends this file list creation subroutine to return to thehost routine.

In the update of file list subroutine to be called in Step S34B, S34I,or S34L, firstly, the entity file in the storage unit 46 is retrieved asshown in FIG. 8 (step S100). Here, it is determined whether theretrieved entity file is a file in the shared (open) folder or not (StepS102). If the entity file is in the shared (open) folder, furthermore,it is determined whether the entity file has already been registered inthe file list or not (Step S104). If the file has not been registeredyet, the retrieved entity file is registered (Step S106).

In Step S102, if it is determined that the entity file is not in theshared (open) folder, further, it is determined whether or not the imageacquisition device information of the retrieved entity file coincideswith the device information of the digital camera 10 (Step S108). Ifthey coincide with each other, the subroutine proceeds to Step S104 toconfirm whether the entity file has not been registered, and the filehas not been registered, the control unit 30 registers it in the filelist.

The control unit 30 determines whether or not all the entity filesstored in the storage unit 46 have been retrieved (Step S110). If allthe entity files have not been retrieved yet, the control unit 30returns to Step S100 then performs operations in Steps S100-S108 givenabove for all the entity files stored in the image data storage unit 46.

Thus, retrieving all the entity files stored in the storage unit 46enables additionally registering the entity files not registered yet inthe file list.

After this, the update subroutine proceeds to processing for deletingthe files which have been registered in the file list but their entityfiles have been deleted from the file list.

In other words, the control unit 30 retrieves the file on the file list(Step S112), and confirms whether or not the retrieved file is presentas entity file in the image data storage unit 46 (Step S114). If thecorresponding-entity file is not present therein, the relevant file isdeleted from the file list for the opening (Step S116).

It is determined whether all the files registered in the file list forthe opening have already been retrieved or not (Step S118). If all theentity files have not been retrieved yet, the control unit 30 returns toStep S112 then performs the operations in Step S112-S116 given above toall the files registered in the file list for the opening. After theperformances have been done to all the files, the control unit 30 endsthis update of file list subroutine to return to the host routine.

As mentioned above, on the second embodiment, the side of the digitalcamera 10 includes a function of restricting access any image data otherthan ones acquired with the digital camera 10 in accessing from thenetwork. Thereby, the data which is accessible from the network side isreduced and the mobile terminal device may simply select the data to bereferred from the network side.

That is, if the digital camera 10 is used as a camera in a general way,the mobile terminal device focuses attention to that the user extremelydesires to watch the images acquired with the digital camera 10, andmakes it possible to externally access only the image files acquiredwith the digital camera 10 in accessing from the network side. Thereby,the mobile terminal device can reduce the number of files which arevisible from the network side and quickly find the desired file.

Further, in a case in which access from outside to the copyrighted filesis allowed, the portable terminal device has to cope with variouscopyright protection functions. However, the mounting of these functionsare complicated and results in an increase in a product cost. Therefore,it is a merit to simply select and eliminate files to be copyrighted andto make it impossible to access the files. However, copyright protectionfunctions develops day by day, and there is a need to revise a selectionmethod in accordance with the development of the protection functionsfor reading and selecting characteristics of the copyrighted files. Inthe second embodiment, the mobile terminal device may limit accessiblefiled to only data which does not produce any problem (with lowpossibility of occurring copyright problem). Then, the mobile terminaldevice can simply select to eliminate the data to be copyrighted; thisis preferable for a beginner.

While in FIGS. 6 and 8, the embodiment have described in a form in whichthe foregoing two identification methods are realized as anidentification method of files to be opened, of course, only eithermethod can be used. For instance, if it is intended to open only thefiles in the shared (open) folder, the mobile terminal device becomesalso able to access files without any problem on copyright such as musicfiles and text files created by the user of the digital camera's userfrom the network.

While the invention has described on the basis of the aforementionedembodiments, the invention is not limited to the aforementionedembodiments, it is needless to say that this invention may be embodiedin various forms without departing from the spirit or scope of thegeneral inventive concept thereof.

For instance, in the first and the second embodiments, in the case wherethe external power source supply unit 52 enables supply power,regardless of the possibility of network communication by means of thewired communication circuit unit 54, the wireless communication circuitunit 38 is started to make wireless network communication. However, itis needless to say that an environment, in which wireless communicationand wired communication coexist therein, may be established, and alsomay switchover to the wired connection in the case where wirelessnetwork connection is not established.

In connecting to the network through the wired communication circuitunit 54, the portable terminal device may perform the same accessrestriction as that of the second embodiment.

Or in the access from the outside is not always restricted, as regardsthe wired communication, the mobile terminal device indirectly connectsto the network through the PC by means of a USB connection. Namely, thewired connection is not directly connected to the network. Conversely,if the wireless connection is directly connected to the network, only inthe case of the wireless connection, the access restriction isperformed. Thereby, only the image data may be viewed in referring fromthe network, and when content is viewed by means of the PC, all thefiles can be referred and the portable terminal device becomes moreconvenient.

While the embodiments have described that the wireless communicationcircuit unit 38 is turned on in the case where the wired connection isnot available, if the power is not supplied from the external powersource, it is preferable to check the remaining capacity of the battery,and not to turn on the circuit unit 38 if the remaining capacity is nothigh. However, if the power supply can be performed through the wiredconnection like the USB connection, the restriction for the circuit unit38 is not limited as given above.

In general, to supply the power by means of the power switch 14, thepower is supplied to each functional unit from the power source circuit48. However, when the external power source connection is detected toturn on the wireless communication circuit 38, it is not needed tosupply the power to all the units the inside of the digital camera 10.In this case, it is enough to supply the power only to the units (e.g.,only to the wireless communication circuit unit 38, the control unit 30,the image data storage unit 46, etc.) which are required for thewireless connection and the access to the inner data.

While the aforementioned embodiments have described by taking thedigital camera 10 as examples, the invention may be applicable to othermobile terminal device such as a mobile information terminal (PDA), amusic reproduction device with a wireless function. As regards a partwhich is derived from the acquired image data can be applicable not onlyto the digital camera 10 but also to other mobile terminal device withan image acquisition function such as a cellular phone with a camera anda PDA with a camera.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, representative devices, andillustrated examples shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

1. A mobile terminal device configured to connect to a network,comprising: a wireless communication interface configured to connect tothe network through wireless communication; an external power sourcesupply unit configured to be supplied power from an outside of themobile terminal device for one of charge and replacement of a built-inbattery; a power supply state detection unit configured to detect that astate, in which power is supplied from the outside to the external powersource supply unit, is attained; a power on/off switch which is operatedby an operator and configured to turn on/off power of the mobileterminal device; a wireless connection on/off switch which is operatedby an operator and configured to turn on/off a wireless functionperformed by the wireless communication interface; and a control unitconfigured to set a state in which the wireless function performed bythe wireless communication interface is available regardless of both thepower on/off switch and the wireless connection on/off switch beingturned off from a previous on state in a case where the power supplystate detection unit detects the state in which the power is suppliedfrom the outside to the external power source supply unit is attained.2. The device according to claim 1, further comprising: a batteryremaining capacity detection unit configured to detect a remainingcapacity of the built-in battery, wherein the control unit makes thewireless communication interface available regardless a detection resultof the battery remaining capacity detection unit after the power supplystate detection unit detects that the state, in which the power issupplied from the outside to the external power source supply unit, isattained.
 3. The device according to claim 1, wherein the power supplystate detection unit outputs a signal on the basis of a detection resultof a voltage to be applied to the external power source supply unit. 4.The device according to claim 1, wherein the power supply statedetection unit is disposed at a prescribed position which is relative tothe external power source supply unit, and utilizes any one of light, amagnetic field and an electric field to output a signal on the basis ofa detected result that an external power source has been electricallyconnected to the external power source supply unit.
 5. The deviceaccording to claim 1, wherein the control unit makes the wirelesscommunication interface available during the power supply statedetection unit detects a state in which the power is supplied from theexternal power source.
 6. The device according to claim 1, wherein thecontrol unit releases setting of the state in which the wirelesscommunication interface is available when the power supply statedetection unit detects interruption of power supply from the outside. 7.The device according to claim 1, wherein the control unit releases thesetting of the state in which the wireless communication interface isavailable when communication with the network through the wirelesscommunication interface is not established within a prescribed timeperiod.
 8. The device according to claim 1, further comprising: a wiredcommunication interface configured to connect to the network by at leastone of a direct wired connection and an indirect wired connection; animage acquisition unit configured to acquire an image of a subject; astorage unit configured to store data of the image of the subjectacquired by the image acquisition unit; and an access restriction unitconfigured to restrict access from a side of the network to the data ofthe image stored in the storage unit through one of an availablewireless communication interface and an available wired communicationinterface.
 9. The device according to claim 8, wherein the accessrestriction unit restricts access from a side of the network only to apart of data to be stored in the storage unit including the data of theimage acquired by the image acquisition unit when the storage unitstores data other than the data of the image acquired by the imageacquisition unit.
 10. The device according to claim 9, wherein theaccess restriction unit restricts access from a side of the network onlyto the data of the image acquired by the image acquisition unit.
 11. Thedevice according to claim 8, wherein the power is supplied only to apart of the mobile terminal device including at least the storage unitand the access restriction unit when the wireless communicationinterface is made available.
 12. A network connection control method ina mobile terminal device which includes a wireless communicationinterface configured to connect to the network through wirelesscommunication, an external power source supply unit configured to besupplied power from an outside of the mobile terminal device for one ofcharge and replacement of a built-in battery, a power on/off switchwhich is operated by an operator and configured to turn on/off power ofthe mobile terminal device, and a wireless connection on/off switchwhich is operated by an operator and configured to turn on/off awireless function performed by the wireless communication interfacecomprising: detecting whether a state, in which power is supplied fromthe outside to the external power source supply unit, is attained; andmaking the wireless function performed by the wireless communicationinterface available regardless of both the power on/off switch and thewireless connection on/off switch being turned off from a previous onstate in a case of detecting the state in which the power is suppliedfrom the outside to the external power source supply unit is attained.13. A mobile terminal device configured to connect to a network,comprising: wireless communication interface means for connecting to thenetwork through wireless communication; external power source supplymeans for being supplied power from an outside of the mobile terminaldevice for one of charge and replacement of a built-in battery; powersupply state detection means for detecting that a state, in which poweris supplied from the outside to the external power source supply means,is attained; a power on/off switch means which is operated by anoperator and configured to turn on/off power of the mobile terminaldevice; a wireless connection on/off switch means which is operated byan operator and configured to turn on/off a wireless function performedby the wireless communication interface means; and control means forsetting a state in which the wireless function performed by the wirelesscommunication interface means is available regardless of both the poweron/off switch means and the wireless connection on/off switch meansbeing turned off from a previous on state in a case where the powersupply state detection means detects the state in which the power issupplied from the outside to the external power source supply means isattained.
 14. A network connection control method in a mobile terminaldevice which includes wireless communication interface means forconnecting to the network through wireless communication, external powersource supply means for being supplied power from an outside of themobile terminal device for one of charge and replacement of a built-inbattery, a power on/off switch means which is operated by an operatorand configured to turn on/off power of the mobile terminal device, and awireless connection on/off switch means which is operated by an operatorand configured to turn on/off a wireless function performed by thewireless communication interface means comprising: a step of detectingwhether a state, in which power is supplied from the outside to theexternal power source supply means, is attained; and a step of makingthe wireless function performed by the wireless communication interfacemeans available regardless of both the power on/off switch means and thewireless connection on/off switch means being turned off from a previouson state in a case of detecting the state in which the power is suppliedfrom the outside to the external power source supply unit is attained.15. The device according to claim 1, wherein the control unit isconfigured to set a state in which the wireless function performed bythe wireless communication interface is available only in a case whereboth the power on/off switch and the wireless connection on/off switchare turned on, in a case where the power supply state detection unitdoes not detect the state in which the power is supplied from theoutside to the external power source supply unit is attained.
 16. Thedevice according to claim 1, further comprising: a wired communicationinterface configured to connect to the network by at least one of adirect wired connection and an indirect wired connection, and whereinthe control unit is configured to set a state in which the wirelessfunction performed by the wireless communication interface is availableonly in a case where the wired communication interface is unavailable,in a case where the power supply state detection unit does not detectthe state in which the power is supplied from the outside to theexternal power source supply unit is attained.
 17. The device accordingto claim 1, further comprising: a battery remaining capacity detectionunit configured to detect a remaining capacity of the built-in battery,wherein the control unit makes the wireless communication interfaceavailable only in a case where the battery remaining capacity detectionunit detects that the remaining capacity of the battery is at least apredetermined capacity, in a case where the power supply state detectionunit does not detect the state in which the power is supplied from theoutside to the external power source supply unit is attained.